I was hoping to take a "confident city cycling" class (typically offered by local bike organizations - in my area it's WABA) before beginning my commute rides. My coworker finally convinced me to meet up with him, then follow him to work - that was this past June. No classes were scheduled for June or July for that matter, so following my coworker was my crash course in city riding instead.

I've also tried to make up for the lack of such a class by joining beginner level group rides. I've learned a lot by going on these rides. I found them through meetup.com.

I also follow other bike commuters sometimes, when they happen to be going the same way. Some of them do run red lights and filter/lane-split, which I try not to do often. There's this one part of the evening commute where I ride on a two-lane street, and would have to change to the left lane, and get into the left turn lane to turn to a particular street. I usually can't do that because there are too many cars going at a speed that blocks me from changing lanes. Some cyclists solve that problem by running a red light in order to get into that left turn lane. I usually pull over to a corner and use the pedestrian crosswalk to get onto the desired street.